The Amazing Success Story of the Red-Breasted Nuthatch – A Remarkable 10 gram Survivor That Punches Well Above its Weight
So, how does a bird weighing less than 10 grams survive in an often harsh environment with an array of predators ready to pounce? It is amazing, but a search through the scientific literature reveals that this plucky little bird has adapted in many different ways to combat the challenges of the Canadian forest. Here are some of the tricks up its sleeve:

Safety in Numbers

From personal experience it is clear that Red-breasted nuthatches are social birds. In fact, after observing and hearing this gregarious tree-dweller perhaps hundreds of times, I have never seen a single member of this species foraging unaccompanied. This observation is corroborated in the literature: An interesting report of a Red-breasted nuthatch in Montana eating snow (Hendricks 2006), despite running water being available nearby, exemplifies this species’ reluctance to stray from conspecifics. In this article a strong case is made that the energy required to melt snow is high, perhaps 13% of the daily energy intake (a cost that could be avoided if running water had been sought), yet this energetic cost seems to be worth it for the bird to remain within the company, and increased collective safety, of its peers.

Language Specialist

The somewhat monotonous (to our ears) call and song of the Red-breasted nuthatch may suggest that this bird is a dull listener, but this far from the case: Nuthatches socialize with Mountain Chickadees and have been observed to understand the complex arrangement of syllables in the chickadee alarm call that correspond to specific threats (Templeton and Greene 2006). This means that more time can be spent foraging if a threat is relatively benign, and more time can be spent mobbing or escaping if the threat is high, which would be case with a small raptor.

Cooperative Nesting

The Nuthatches relationship with chickadees does not stop there. Intriguingly, nuthatches have also been observed sharing a nest with their arboreal counterparts. Researchers reported that a nest was found near Williams Lake, BC containing two Red-breasted nuthatches and three Mountain Chickadee nestlings. After first being attended by a pair of adult chickadees, the young were then visited by an adult female Red-breasted nuthatch. The researchers suggest that a reduction in nest cavity availability may have been a factor in this inter-specific cooperative behavior (Robinson et al. 2005).

Rapid Response to Changing Environments

The Red-breasted nuthatch takes advantage of outbreaks in mountain pine beetle (Dendroctonus ponderosae) and can adjust its nest site selection and rate of cavity excavation in response to the pulse in food availability (Norris and Martin 2012). That the Red-breasted nuthatch can respond to changes in food availability by excavating new cavities, suggested to be an apomorphic (novel to its clade) trait (Pasquet et al. 2014), or induce irruptive behavior if food is scarce, is testament to this birds remarkable adaptability.

 

References

BirdLife International. 2012. Sitta canadensis. The IUCN Red List of Threatened Species 2012: e.T22711196A39658922. http://dx.doi.org/10.2305/IUCN.UK.2012-1.RLTS.T22711196A39658922.en

Campbell RW, Dawe NK, McTaggart-Cowan I. 1997. Birds of British Columbia, volume 3 : Passerines, flycatchers through vireos. Vancouver, BC, CAN: UBC Press.

Dye K, Fiszer M, Allard P. 2009. Birds new to norfolk. Sheringham, UK: Wren Publishing.

Hendricks P. 2008. Red-breasted nuthatch eating snow. Northwestern Naturalist 89(1):53-4.

Ghalambor, Cameron K. and Thomas E. Martin. 1999. Red-breasted Nuthatch (Sitta canadensis), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/459 doi:10.2173/bna.459

Norris AR and Martin K. 2012. Red-breasted nuthatches (sitta canadensis) increase cavity excavation in response to a mountain pine beetle (dendroctonus ponderosae) outbreak. Ecoscience 19(4):308-15.

Pasquet E, Barker FK, Martens J, Tillier A, Cruaud C, Cibois A. 2014. Evolution within the nuthatches (sittidae: Aves, passeriformes): Molecular phylogeny, biogeography, and ecological perspectives. Journal of Ornithology 155(3):755-65.

Robinson PA, Norris AR, Martin K. 2005. Interspecific nest sharing by red-breasted nuthatch and mountain chickadee. The Wilson Bulletin 117(4):400-2.

Sibley D, Elphick C, Dunning JB. 2001. The sibley guide to bird life & behavior. Alfred A. Knopf New York.

Templeton CN and Greene E. 2006. Nuthatches eavesdrop on variations in heterospecific chickadee mobbing alarm calls. Proc Natl Acad Sci U S A 104(13):5479-82.

Townsman D. 2008. Nature notes; the red-breasted nuthatch (Sitta canadensis). Daily Bulletin;3.